xlock locks the X server till the user enters his/her password at the keyboard. While xlock is running, all new server connections are refused. The mouse cursor is turned off. The screen is blanked and a changing pattern is put on the screen. If a key or a mouse button is pressed then the user is prompted for the password of the user who started xlock. . This version is built without additional OpenGL and XPM modes. The companion package xlockmore-gl contains them. This is the only difference between the two packages.